[Towertalk] Help locating freestanding tower

Tom Rauch W8JI@contesting.com
Sat, 15 Jun 2002 07:42:48 -0400


> you dont want grade 5 for a tower, or stainless, stainless is too weak
> and grade 5 is to hard, theyll break under stress, you want A325 type
> 1 or 2, its a structural grade bolt, itl  stretch under high stress
> instead of shearing off at the head, trust me ive been stackin iron
> for a long time

With free-standing towers, especially those with flange-type joints 
that is true. 

Cross-bolted tower joints do not put stress on the bolts, other than 
modest cutting (shear) pressure! The bolts used in telescoped cross-
bolted leg joints are far from critical, as long as they are nearly 
as hard as or harder than the mild steel .050-.125 inch thick legs 
(that in some towers are welded, softening them further from the 
heat) trying to "cut" the bolt. 

Stainless bolts or even unhardened mild steel bolts are perfectly 
fine for guyed towers with cross-bolted telescoped leg joints. The 
main concern is rust.  Flanged joints, especially in self-supporting 
towers, should always use the manufacturer's recommended hardware.73, 
Tom W8JI
W8JI@contesting.com